You and Fluttershy have a very loving relationship. It's very high quality. It makes you feel good about being a Human in Equestria. Like your being there is a good thing, and other folks seem to like it too. But when it comes time for you two to finally get intimate, Fluttershy has some pretty rough news for you. It seems that ponies and humans having sex would result in the degradation of your moral character, and she just can't do that to you! For your own good! This is news to you, both that she feels this way about sex and that she thinks you have moral character to begin with...

WARNING: Contains eroticism. You know. That thing that is always morally bad in stories and makes us worse people for reading/creating.